This invention relates to animal feeders and is particularly directed to a feeder for hogs in which the flow of feed into a trough is under control of the hogs.
In the past many different forms of hog feeders have been proposed including some having a stationary hopper from which feed is disposed into a trough and others including a rotary hopper which is moved by the pigs' snouts so that the flow of feed can be controlled by the animals at the feeder. Among typical prior art patents disclosing hog feeder are Thibault U.S. Pat. Nos. 4,353,329 and 4,462,338. Each of these patents discloses feeders employing stationary hoppers. In the feeder shown in U.S. Pat. No.353,329, feed drops from the central portion of the hopper and is pushed outwardly by spoke-like arms which are rotated by the hogs. In this patent the feed rate is adjusted by regulating the size of the openings in the bottom of the hopper. In the second Thibault patent, the feed rate is adjusted by raising or lowering a conical member.
Other patents disclose rotary hoppers. For example, Brackenbury U.S. Pat. No. 1,292,693 discloses a hog feeder including a rotary hopper and radial arms. Hogs push against these radial arms to turn the hopper. Another patent of this type is Royer Pat. No. 1,350,523. In this patent, the livestock push against the hopper causing it to rotate. In both the Royer and the Brackenbury patents, feed is distributed outwardly to a peripheral trough by means of an inverted cone. Fouts U.S. Pat. No. 1,392,004 and Boland U.S. Pat. No. 2,500,270 each disclose a hog feeder including a rotary hopper. This hopper can be raised and lowered to control the rate of feed discharged. Another version of a feeder including a rotary hopper is Casper U.S. Pat. No. 2,153,455. The feeder shown in this patent includes a plurality of spokes which cause the feed discharged from the hopper to be spread outwardly toward a peripheral rim.
Each of the feeders disclosed in these patents as well as the feeders actually in use at the present time are subject to one or more defects such as undue complexity, excessive maintenance costs, inefficiency of feeding, limitations as to the type of feed which can be dispensed, difficulty in operation by the hogs making the feeder unsuitable for small pigs, and the like.